This is a project to study the long-term effects of somatostatin analog treatment on acromegaly. Patients are treated unblinded with somatostatin analog as long as it is medically necessary. Treatment and prevention of gallbladder sludge and gallstones, common side effects of somatostatin analogue treatment, is being done with ursodeoxycholate, a bile salt analog that dissolves gallstones. Patients taking somatostatin analogue are treated with ursodeoxycholate if they have gallstones or sludge, and patients without these complications are randomized for placebo controlled treatment with ursodeoxycholate to attempt to prevent sludge formation. Our experience with gall-bladder changes in acromegaly has been recently reported. Five patients have been randomized to masked treatment with ursodeoxycholate, and seven patients have been treated unmasked for sludge or stones. To date no change in pre-existing gallstones or sludge has been seen, and no patient on masked treatment has developed sludge.